1. Field of the Invention
This invention relates to welding assemblies and in particular to a spot welding assembly for electrical resistance welding and particularly for precision welding of small components. The assembly consists of a carrier fixture which guides a feed slide block and an electrode slide block carrying the welding rod, the electrode slide block being spring loaded and being guided by ball bearings within the feed slide block.
2. Prior Art
In precision spot welding it is essential to guide the welding rod into contact with the work piece with an exactly controlled contact pressure. Moreover it is particularly important to avoid the generation of any torsion moment when pressing the electrode against the work piece. Any such torsional moment could, in some cases, result in an offset movement of the electrode tip at the welding point. Any offset, including a small rotation of the electrode tip, during pressure contact of the work piece, can result in damage to the work piece. For example, it is possible that during triggering of the electrical current welding pulse, that the heating of the parts to be welded at the welding location can be non-uniform due to a change in the contact cross section of the contacting welding rod. Moreover it is always possible that such movement of the rod or rod tip during the application of the pressure contact could cause a slight movement of the work pieces with respect to one another.
In order to avoid these problems, it is desired to construct the welding assembly in such a manner that the welding tip is precisely movable, is not subjected to undesired movement and is precisely applied to the work piece with the desired pressure.